Expansible reamer



1, J. M. MARTY, JR

.EXPANSIBLE REAMER Filed Feb. 20, 1924 Cab Patented Jan. 1, 1929.

JOHN M. MARTY, Jn., or CLEVELAND, oirro.

xrANsiBLn BEAMER.

Application 'led February 20, 1924. i Serial 110.694,087.

This invention relates generally to metal cutting tools and more lparticularly to expanding or adjustable reamers.

Tools of this kind are usually formed with a central longitudinal bore and are longitudinally slotted. The expansion is accomplished by the movement ot' a wedge or expander', and this'wedge or expander is usu ally moved by means of a single screw or thread and while a fairly gradual expansion can be had there arecertain instances where an exceedingly minute expansion or adjustment is desired and which cannot be readily accomplished through the medium of a single screw and thread.

The object of my invention, therefore, is to overcome these various di'liiculties, that is to say, to provide an expansiblentool in which the expansion can be exceedingly line and gradual, one in which the amount of expansion can be accurately determined, and one which can be locked after such expansion and remain so until released.

l/Vith these various objects in view, the invention consists primarily in providing a dierential screw 'for elfecting the exceedingly fine andV gradual movement of the expander, and the invention also consists in providing the expanding means with graduations whichare visible from the exterior of the tool, and the invention also includes means for effectively locking the expander against movement.

The invention consists also in certain details of construction hereinafter fully described and set forth in. the appended claims.

1n the drawings forming a part of this specification, Fig. 1 is a side view-of an expanding reamer` constructed in accordance with and embodying my invention; Fig. 2 is a sectional view oit the same partly in elevation; Fig. 3 is a transverse sectional view on the line 3-3 of Fig. 1; Fig. 4 is an end view of a modified form of tool;` and Fig. 5 is a longitudinal sectional View on the line 5 5 of Fig. 4.

In carrying out my invention I employ a reamer body 10 formed with the usual cutting surfaces 11 and longitudinal slots are formed in the body in order to permit the radial expansion of the tool. The body is bored longitudinally from end to end and the interior oit' the bore is formed with the inclined or tapering surfaces 13 and the bore yis also internally threaded as shown at 14.

Adjacent to thathreaded portion 14 the bore is made smooth and somewhat larger as indicated at 15. An opening 16 is produced in the body in line with the portion 15, this opening being counterbored ,upon the exterior` as m'ost clearly shown in Figs. 1 and 2.

An vexpander member 17 is inserted in the bore 'from the opposite end, the outer end 18 of said expander fitting snugly within the bore as shown while its inner end is made tapering or wedge shape as shown at 19, this tapering or conical end 19 being adapted to contactwith the tapering or inclined surfaces 13 for the purpose of expanding the tool. .The expander 17 is internally threaded as shown at 20.

A longitudinal groove 21 is produced in the cylindrical end 18 of the expander and a key pin 22 passing through the body into the longitudinal slot 21 holds the Iexpander against rotationbut permits thev same to move longitudinally in or out as desired.

The expander is actuated byva member fitted into the opposite end of the bore, said member comprising the smooth portion 23 kwhich ts into the portion 15 ot the bore and is externally threaded as shown at 34 for engagement with the internal screw threads 14 ot .the bore, reduced at 25 and provided with a threaded end 26 which screws into the threaded portion 20 of the expanding wedge or conel 19. The threads 34 and 14 are of diilerent pitch from the threads 26 and 20 so that a diHerential movement is obtained between the actuator and the expander.

In practice I prefer to out the threads 34 and 14 upon the 27 pitch While the threads 26 and 2O are out upon the 24 pitch. This i ratio will give an exceedingly ine adjustment effecting an exceedingly fine and gradual expansion of the reamer whichis necessary in certain classes of work.

The cylindrical portion 23 has graduations 27 arranged thereon and extending entirely around the` same, these graduations being visible through the opening; 16 and a gage mark 27 a is placed upon the counterbore of the opening 16 and with which the graduations can be caused to register, and by moving the actuator to either direction the amount of movement can be gaged.

A socket recess 28 is provided in the end of the actuator tor the insertion of a suitable tool for turning the same. A screw plug 29 is screwed into the end of the expander and is adapted to be brought into lockedl engagement with theend of the differential screw f for preventingY further 4movement and it is obvious that when this locking screw is brought into ,-operationythe adjusting mechanism of the tool is securely locked `and consequently the tool/can be removed from the machine, laid aside and replaced without dangerof the `zuljuslnnent being disturbed in the meantime.

In the construction-showiji in Figs. lhand 2, the expansion intermediate the ends of the reainer.`v In theconstruction shown in Figs. l and 5, theexpansion takes'placel at the end of the reamer. y

In-this-for1n of device 30 indicates the body of thetool having the cutting-surfaces 31.y Longitudinalslots 32fextend to theend ofY the tool. A central longitudinalv bore is'provided' andthe outer` end Aof this bore is tapered as shown-at `The extreme inner end'of the -bore is internallythreac ed as shown' at 34. A tapering or conical expander 35 is inserted in the tapering bore 33, this tapering expander 4being internally threaded as shown at 36 in whichlits the screw 37 this screw vhaving an inwardly extending portion v38qexternall'y threaded as shown at 39 for engagement with the threaded portion' ofthe bore while the threaded portion'37 and the screw engages the threads 36.0f the expander, and it will be noted that the threads 37 and 36'are of different pitch from thethreads 39 and 34, the threads 37 being cut upon the 27 pitch while thc threads 39 are cut upon the 24 pitch, as previously described, so that a. differential movement between the screw and expander can be had.

Locking screws 40 pass through longitudinal slots ll cut in the body of the tool, these pins holding the expander against rotation and also by turning the same down, securely lock the .parts against further movement.

It willv thus be seen that I provide an exceedingly simple and eflicient 4expanding rcamer capable of very line adjustment due to the ratio of the threads of the differential screw, and it will-also be noted that `the adjustable parts can be securely locked against movement in either direction when desired. i Y l In.y the construction shownf'in Figs. 4 and 5*,.graduations can be made upon the end of the screw and the expanding member in order to gage the amount of movement of saidscrew. A socket 42 will be provided in the end of the actuator for the reception df the proper "operatingvtoot l Having thus described my invention what` Il-claimis:

15in a toolfof thefkind described, 'the combination with` a body longitudinally bored? and lslotted and having exterior cutting surfaces, said'vbore having a threaded portionand aftapering portion spaced from the threaded portion,-of. an expanding inemberexternaklly tapered and internally thread ed, `and keyed tow'preventfrotation while moving longitudinally, andanactuator arranged insaid bodyl and having a threaded portion engaging `the threaded portion of the' body/andanother threadedI portion engaging the internal threads of the expander, the threads of the actuatorfbeing =of-the same 'characterI but of different pitch, i said expander by its movement engaging'ithe tapered and slotted po'rti'onof the body and expanding thecutting surfaces.

fil)

2. In a tool of: the kind described, the i` combination with a body longitudinally bored `and"'slotted` andvhaving exterior cutting surfaces, said'bore having a threaded portion and a tapering portion spaced from the threaded portion, of' an vexpanding member externally4 tapered and internally threaded, `and keyed to prevent rotation while moving longitudinally, and an actuator 'arrangedvin said body and having a threadedv portion engaging lthe 4threaded portion ofthe body andanother threaded portion engaging the'internal threads of the expander, the threads being'o-fthe same char acterlbut of different pitch, and means arranged within the expander for limitingthe movement lof the actuator and holding vsaid expander and 'actuator against movement.

In testimony whereof, I hereunto aflix my signature.

JonNMf MARTY; JR. 

